View Full Version : Wanting to try the 2 bath Pyrocat developing

Steven Ruttenberg
5-Sep-2018, 16:34
I downloaded this write up http://pyrocat-hd.com/html/TwoBathPyrocat.html and was going to order from this site http://stores.photoformulary.com/pyrocat-hd-dry-or-liquid/

I have many black and white negatives from my trip this weekend that I intentionally exposed for the darkest part of the scene at Toroweep Grand Canyon. Lot's of clouds, very bright in spots and not till the next day did I use a Grand ND filter. Anyway, I am interested in the idea of being able to pull out the darkest shadow detail and not blow out the highlights.

Questions are:
1. Do I have the right site and chemicals to do this? If not, where should I get the right chemicals?

2. I am using Tmax100, what exactly are the development times? Should I increase times in A and B or decrease? What would be a rule of thumb? Or is just develop using the listed times in the two bath write up?

3. Mixing ratios are 1 part A to 20 parts water and 1 part B to 20 parts water. How many sheets of 4x5 can you get out of this if I mix a 500 ml solution? 4, 8 or 12?

4. According to the 2 bath write up you rinse after each stage for 15 seconds. At the end you run thru your typical stop bath, fixer, etc as normal.

I am wanting to try this because I want to see if this process is will do what it is supposed to do in pulling out shadows at the same time saving the highlights.

I know I am probably not understanding this fully, but I really want this to work. It makes metering much easier in extreme situations of bright back lit clouds and deep, dark shadows like those you run into at the Grand Canyon and in back lit trees, like Aspens at sunset/sunrise.

Also, is there a similar process that will work with color negatives?

Lastly, could I achieve the same result by pushing or pulling during development? Any links/guidance is helpful as pushing and pulling film is my next lesson to learn. Would you say expose for the shadows and then pull the negative a certain number of stops or expose for the highlights and then push the film?

Sorry for such a long post. Need to order chemicals so I can try the 2 bath Pyrocat develpment.

Ken Lee
5-Sep-2018, 16:48
Handling 14 zones is no problem, but before you develop important negatives with Divided Pyrocat (or any new developer) you should get your technique established.

You might find it helpful to note the discussion of wetting agent, agitation and rotary development:



5-Sep-2018, 22:45
As Ken says; try it out. I tried it and I found I really needed a 1+10 dilution for the A bath and multiple iterations between A and B to develop xray to satisfaction. Tmax is a thinner emulsion that will soak up even less developer, so you'd probably need an even higher concentration for A. Since you cannot develop by inspection with tmax, testing is essential before you commit valuable negatives. To be honest, I think N- development is a safer and more straightforward method.

As to color: 2-bath development will work to some extent, but color balance will be off and probably to a large extent, and you may run into crossover issues. I wouldn't recommend it. N- development is possible with C41 within certain boundaries, with loss of saturation and acutance. C41 (and E6 as well) really work best within the official parameters.

6-Sep-2018, 04:17
I tried Pyrocat two bath. The method uses a lot of developer. I found it compressed the zones to match my paper, but didn’t see any improvement over my normal method of minimal agitation with dilute developer. As Ken said, experiment with some test negatives first.

6-Sep-2018, 11:50
I never had great results with divided Pyrocat - even overexposing the film several stops I still got thin negatives. Did everything as recommended in the threads above. It also uses a lot more developer so kind of expensive. I would just use regular Pyrocat development but 20-30% less time.

Doremus Scudder
6-Sep-2018, 13:23
Another thing to try is SLIMTs (selective latent image manipulation techniques). Google search on SLIMT an David Kachel for his articles on the subject. It would be wise to test out the exact dilutions and times first, of course, before using the technique on important negs. I've had really good luck with SLIMTs for negative contractions up to N-4 and rather normal development times with no appreciable loss of shadow detail. It is my go-to technique for anything that needs more than an N-1 contraction.



Ken Lee
6-Sep-2018, 13:43
The ability of Divided Pyrocat to accommodate scenes of extreme contrast is astonishing when you first encounter it.

I haven't used Divided Pyrocat in a while because of uneven development. If I started again - with sheet film particularly - I would acquire a rotary system to ensure the film is agitated continuously and evenly.

Another striking advantage of this approach - which has to be seen to be appreciated - is the fineness of grain. Development proceeds very quickly on the surface of the film.

Sandy King showed me a very large print he made from a 6x7 negative on Fuji Acros: around 30 or 40 inches wide if I recall correctly. The image was perfectly sharp but no grain was visible at all.

Steven Ruttenberg
6-Sep-2018, 17:10
This is like going back to chemistry and science class in college. I will look up the slimts approach as well. Amount of developer is not as important to me as getting the image developed correctly. Sounds though, that if I do this right, it will be an excellent way to develop images of high contrast, especially when you do not use a grad nd as an example.

Steven Ruttenberg
6-Sep-2018, 21:37
Okay, I just ordered the Pyro at HD liquid. If I read the description right, it makes 10 liters. That's a lot. Will make a couple test runs before trying on my Grand Canyon shots.

Negatives I will be using are tmax100 and 400, Acros100 HP-5 400 and D100. Using sp445 tank. What times to use. I see 5 x 5 for tmax 100 if doing two bath, same for other films? What all to watch out for?

Tin Can
7-Sep-2018, 05:08
Looking forward to your results and opinions.

Steven Ruttenberg
8-Sep-2018, 11:50
I as well. I am gonna take some test shots, ones I can easily redo a typical landscape scene I would shoot that has a high contrast between darkest shadows and the brightest parts of sky of two different scenes. I will expose the darkest area to be zone v, take two images of each scene with tmax 100 and HP5 400. Develop one set normally in tmax developer and the other set in the two bath. Then I can evaluate against "standard" processing and 2-bath. I hope to have lots of back lit clouds as this would privide a big extreme between lights and darks.

Next time, I will try the slimts that was suggested above.